If Nigel Farage stands in Chris Huhne's seat, the Conservatives should not contest it

Chris Huhne's resignation as the member of Parliament for Eastleigh will mean a difficult by-election for the Conservatives and the Lib Dems. Huhne won in 2010 with a majority of just 3,864, making Eastleigh one of Grant Shapps's target seats. This is particularly awkward for David Cameron. In order to reassure his sceptical backbenchers, who think he's made far too many concessions to Nick Clegg as it is, he'll have to go all out to win, with frequent trips to the constituency. Not only will that mean an unseemly punch up between the Coalition parties – particularly if Clegg is out on the stump in Eastleigh, too – it will be hugely embarrassing for the Prime Minister if the Tories lose. Just the sort of set back, in fact, that will fuel more rumours of a leadership challenge.

But there's a solution at hand. According to Guido Fawkes, Nigel Farage is considering a run in Eastleigh, a seat he contested in 1994. Grant Shapps should get on the phone to Farage straight away and offer him a deal. The Conservatives won't contest the seat provided Ukip doesn't field candidates against any sitting Tory MPs in 2015. The deal should not be made public, of course. CCHQ will announce it isn't fielding a candidate in deference to the party's Lib Dem allies – thereby avoiding a row – while privately letting the Parliamentary Party know that it's secured in informal electoral pact with Ukip that has protected its more vulnerable members. Farage could then announce Ukip won't be opposing any sitting Conservative MPs on the night be romps home to victory – not on account of a sleazy, behind-the-scenes deal, but because that's the best way to secure an in-out referendum in the next Parliament.

The best thing about this secret deal would be that it could easily lead to a second pact between the two parties whereby Ukip agrees not to field candidates in those constituencies where the Tories came second in 2010 and the Conservatives agree not to field candidates in, say, a dozen seats selected by Ukip. Again, this pact wouldn't be official, but if the parties want to help each other out on the ground, so much the better – and they can begin working together in Eastleigh. I'm a member of the Tory Party, but if we don't contest Chris Huhne's seat I will happily campaign for the Ukip leader.

Won't happen, of course. But how exciting British politics would suddenly become if it did.